Bought my H22A Yesterday and...

[BustedLX]

Hello everyone. Well I finally found a reputable importer in South Florida and purchased my H22A Yesterday. I'm going to start the swap next week as soon as the parts I ordered from Honda arrive (engine mounts, ball joint boots, etc.).

Anyway I was looking over the engine and see allot of vacum lines and other catylist system components. I want this thing to run and idle as it should in a Prelude. So I'm doing all my research now before I begin so I don't get any unpleasant surprises.

The main thing that has me curious is the Fuel pressure regulator. There is a vacum control solonoid connected between the FPR and intake manifold as if the ECU has the ability to regulate the fuel presure depending on throttle position and engine load.

My question is how has everyone connected this peice of equipment? I luckly got the complete engine harness with the harness that goes threw the firewall to the ECU uncut. So if need be I can fallow the wire to it's location in the ECU plug but I was just wondering if anyone had already done the research on this.

Also is there anything else in reference to the catylist system I should look into?

Thanks.

[BustedLX]

Here are the pictures of the part I'm talking about.




You're H22 didn't come with that?

Anyone else?

[BustedLX]

Ok I fallowed it all the way back to the ECU. It's a white/yellow wire that goes to pin A10 on the ECU. It's uses the same multi-ground as the IAB.

I don't know if it's an Automatic transmission thing or not but tomorrow I will check some other places to see if I can find out what that pins designation is. So far on all the documentation I have (Mostly civic since that's what I mostly do swaps on) that pin is not used.

I know someone with a 5-Speed Prelude with a JDM H22A. I'm going to check his car to see if he has it.

I'll post what I find out.

[ACCLUDE91]

I believe you are referring to the EGR control solenoid. Yeah, All H22's should have that. Pin A10, is not used in the USDM or JDM swap so that's not the pin it's going to be. It should actually go to pin A11 and should be a black/yellow wire at the solenoid, but changes to a pinkish red wire and should be red at Pin A11 at the ECU plug. You mentioned that it was a white/yellow wire and there shoudln't be ANY white/yellow wires going to the A harness of the ECU. If there is, I'd be questioning whether you got the right wire harness or not. That I can tell you from experience. Good luck on the swap! It's not all that difficult and you shouldn't have a problem since you have previous motor swapping experience. Hope that clears it up for ya a little

[BustedLX]

That thing that is circled in the pics is some type of vacum solonoid that is controlled by my Automatic P13 ECU. It takes the vacum line from the plenum then it's out line goes to the FPR. Just reviw the pix! It's control wire runs to A10 (A plug 5th pin over bottom row). I have the complete harness from the engine threw the firewall to the ECU and I fallowed it all the way threw to the computer so I know I'm right.

My question is what the hell is it?

I checked out my friend's 1995 Prelude SI that we did a JDM H22A swap on because I didn't remember that solonoid and he didn't have it, also pin A10 on his harness was unused. I'm probably just going to remove it and not use it. Since I'm converting my P13 to manual it shouldn't matter because the manuals don't seem to have it but I'm still curious as to what it is.

P.S. I'll post pix of the infamous White/yellow wire in the A harness I'm not supposed to have later along wiht pix of the power steering for the other thread.

[ACCLUDE91]

I have a JDM with manual tranny in my car and it did come with that as well. I will pin it out at the ECU for you and tell you where it's supposed to go to. Automatic or manual doesn't matter, pin A10 is not used at all! I'm heading to the shop in a littlebit and I'll pin it out for you then. My last reply was just me looking at a wiring diagram trying to figure it out, but this time, I will stick my multimeter up to the wires and physicallly pin it out.

[BustedLX]

Originally posted by ACCLUDE91
I have a JDM with manual tranny in my car and it did come with that as well. I will pin it out at the ECU for you and tell you where it's supposed to go to. Automatic or manual doesn't matter, pin A10 is not used at all! I'm heading to the shop in a littlebit and I'll pin it out for you then. My last reply was just me looking at a wiring diagram trying to figure it out, but this time, I will stick my multimeter up to the wires and physicallly pin it out.

So your manual did come with that? Intresting I wonder why others on this forum, my friend, and some other manual H22A's didn't come with it.

Anyhow thank you but I don't need you to pin it out and tell me where it goes, I already did that. I used my multimeter. I don't want to come off as a dick but it does go to pin A10. That's what made me so curious because in other Honda OBD-1 applications (also without this device) A10 is an unused pin.

Anyhow here are the pix with the wire clearly in spot A10. The color didn't come out unfortunately but it is white with a yellow stripe.






I just want to know why this device is there and what advantages it provides over vehicles without it. The rest of the research I can do on my own.

[ACCLUDE91]

I don't doubt what you have right infront of you, but I can tell you, Pin A10 is not going to be used. I couldn't tell you why there is a pin there. That's something I've never seen before and I've looked at quite a few H22 and F22 ECU harnesses and NONE of them have ever used pin A10. The Helms manual for both Accords and Preludes mention nothing about A10 ever being used. I'm just as confused as you at this point. I'd like to find out what the differences are in the wiring. My swap only came with the motor harness but not the harness that runs to the ECU so I had to custom wire it from the motor to the ECU and that's why I don't have a pin going to A10 on my setup. So if that device is supposed to go to pin A10, then I do not have it hooked up and it does not negatively affect how my motor runs. When the motor is all in and hooked up and you go to start it, listen right at that unit cause you can hear the excess pressure from the FPR being let off through it. It's almost as if its a part of the FPR. It's some sort of valve related to the FPR. I wish I could help you a little more on that but like I said, I'm just as confused as you are right now. If it is supposed to go to Pin A10 like you pinned out, than mine is not connected and the motor runs fine so you'd be fine not using it, but like you, I'm curious if there is a bennefit to using it?!?!?!